Polymerizable emulsifying agent

ABSTRACT

Compounds having the formula   wherein R is alkyl group having 6 to 22 carbon atoms, M is H, Li, Na, K or NH4 and n is an integer of 2 to 4, inclusive. The compound is useful as polymerizable emulsifying agent, and enables to improve properties of produced polymer and to provide a modacrylic fiber superior in heat stability and fastness to light. The aqueous emulsion polymerization of Beta ethylenically unsaturated monomer by the use of the polymerizable anionic emulsifying agent is capable of preventing a discharge of an environmental pollutant.

United States Patent [1 1 Kozuka et al.

[111 3,907,870 1 Sept. 23, 1975 POLYMERIZABLE EMULSIFYING AGENT [73] Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha, Osaka, Japan [22] Filed: Sept. 20, 1973 [21] Appl. No.: 399,128

[30} Foreign Application Priority Data Sept. 20, 1972 Japan 47-94797 [52] US. Cl. 260/485 J; 260/29.6 AN; 260/29.6 SQ; 260/78.5 B; 260/78.5 E; 260/78.5 CL; 260/78.5 I-IC [51] Int. Cl. C07C 69/60 [58] Field of Search 260/485 J [56] References Cited UNITED STATES PATENTS 2,964,557 12/1960 Niederhauser et al 260/486 R 3,147,301 9/1964 Sheetz 260/485 J 3,304,315 2/1967 Nevin ct al... 260/485 R 3,343,964 9/1967 Thomas 260/485 R 3,391,183 7/1968 Dowbenko... 260/485 R 3,551,479 12/1970 Emmons 260/485 J 3,579,565 5/1971 Zaslowsky et a1 260/485 J 3,679,737 7/1972 Pohleman et al. 260/485 J 3,830,830 8/1974 Cleveland et al. 260/485 R FOREIGN PATENTS OR APPLICATIONS 1,161,668 8/1969 United Kingdom 260/485 J Primary Examiner-Robert Gerstl Assistant Examiner-E. Jane Skelly Attorney, Agent, or FirmArmstrong, Nikaido & Wegner [57] ABSTRACT Compounds having the formula wherein R is alkyl group having '6 to 22 carbon atoms, M is H, Li, Na, K or NH and n is an integer of 2 to 4, inclusive. The compound is useful as polymerizable emulsifying agent, and enables to improve properties of produced polymer and to provide a modacrylic fiber superior in heat stability and fastness to light. The aqueous emulsion polymerization of a, B-ethylenically unsaturated monomer by the use of the polymerizable anionic emulsifying agent is capable of preventing a discharge of an environmental pollutant.

4 Claims, 9 Drawing Figures US Patent S ept. 23,1975 Sheet 1 013 3,907,870

CH-COOH WAVELENGTH-am) PERCENT TRANSMISSION b 0) oo o O o 3600 3200 2800 2400 2000 1900 1800 1700 1600 1500 1400 1300 1200 11001000 900 800 700 600 WAVENUMBERCm I CH-COONa WAVELENGTHmm,

gs 3.0 3.5 4.04.550 5.5 6.0 6.5 7.0 7.5 so 13.59.09.510 11 1213141516 0 3600 3200 2800 2400 2000 1900 1800 1700 1600 1500 1400 1300 1200 11001000 900 800 700 600 WAVENUMBERCm '1 CH-COO- CH WAVELENGTH! m1 2)3 SO3Na PERCENT TRANSMISS 3600 3200 2800 2400 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 WAVENUMBER'Cm'1 US Patent Sept. 23,1975 Sheet 2 of 3 3,907,870

CH-COOH WAVELENGTH m1 105.5 39 3.5 494.550 5.5 6.0 6.5 7.0 7.5 8.0 859.095") 11 1213141516 7) 280 "zsf n: no WA W '2 I 6 D5 LL] 0- WAVENUMBER Cm H-COONa. WAVELENGTH 4m) 002.5 3.0 3.5 4.04550 5.5 6.0 6.5 7.0 7.5 8.0 85909510 11 1213141516 PERCENT TRANSMISSION 8 3600 3200 2800 2400 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 WAVENUMBER Cm CH-C 00- CH2 -3 0 11a WAVELENGTHMm) PERCENT TRANSMISSI b 6') O O 3600 3200 2800 2400 2000 1900 18001700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 WAVENUMBERCm POLYMERIZABLE EMULSIFYING AGENT BACKGROUND OF THE INVENTION able emulsifying agent, and more particularly relates toa novel polymerizable emulsifying agent providing an aqueous emulsion polymerization process for a,B-ethylenically unsaturated monomer which does not discharge an environmental pollutant such as emulsifying agent, water-soluble polymeric material, water-soluble oligomer or oil-soluble oligomer in such a step as filtration or washing of polymer by polymerizing the polymerizable emulsifying agent and the specific a,B-ethylenically unsaturated monomer polymerizable therewith. I

The present invention further relates to a novel p'olymerizable emulsifying agent which is polymerized with acrylonitrile to provide a modacrylic fiber superior in heat stability and fastness to light.

The polymerzable emulsifying agent of the present invention is sulfoalkyl-alkylmaleates having one hydrophobic alkyl group and one hydrophilic sulfoalkyl group which is prepared from maleic anhydride, higher alcohol and one of propanesultone, butanesultone, so-

dium 2-oxy-ethanesulfonate and sodium isethioriate The polymerizable emulsifying agent of the invention is effectively employed in a polymerization of,a,[3-ethylenically unsaturated monomer so as to prevent discharge of environmental pollutants by industrial wastes, also effectively employed for improving properties such as heat stability, mechanical property, transparency and processing property of synthetic resins such as copolymer of acrylonitrile and others.

An aqueous emulsion polymerization process has been utilized to prepare a polymerized material in a field such as synthetic rubber, synthetic resin,-coating material or synthetic fiber. In such a process, after'polymerization, the polymerized material is taken out as an intermediate product or a product through steps such as filtration from an aqueous medium, washing However, a conventional emulsifying agent is not and drying, and frequently environmental pollutants such as watersoluble polymeric material, water-soluble or oil-soluble oligomer, which are by-produced in polymerization, as well as emulsifying agent'are discharged into drainage at the time of filtration or washing of a polymerized material. In recent years, the recognition concerning toxicity of emulsifying agent becomes deepened, and also a watersoluble polymeric material problem as one of an environmental pollutants, and a countermeasure against a polymerization drainage as stated above has been strongly desired.

Hitherto, an aqueous emulsion polymerization process has been utilized in preparation of various polymers with industrial advantages that it produces less I scale or coagula in comparison with another aqueous polymerization process, reaction heat in polymerization is readily removed and polymerization reaction can be stably carried out even at high monomer con- I centration.

polymer particle. Then various unfavorable things arise since itdoes not bone chemically to a polymer. For instance, in case of processing'a polymer to shaped article such as film, fiber, or thelike, an emulsifying agent must be removed off completely from polymer since an emulsifying agent remaining in polymer makes the properties such as transparency, heat stability, mechanical property, fastness to light and water resistance worse. For the removement ofan emulsifying agent, much amount of wash water must be employed, which is still insufficient. v

Ont he other hand, therehas been known a polymerizable aninonic emulsifying agent, for instance, sulfo ester of a-methylene carboxylic acid derivatives such as sodium 2-sulfoethyl-q-methylacrylate, sodium 2 sulfoethyl-a-butylacrylate and sodium 2-sulfoethyLa-hexylacrylate, monoalkylitaconoxypropanesulfonate derivatives such as potassium monolaurylitaconoxypropanesulfonate and sodium monocetylit-.

aconoxypropanesulfonate, sodium p-styrylundecanate, sodium l0-acrylamidestearate or sodium 10- acryloxystearate. .These polymerizable emulsifying agents contribute to improvethe mechanical stability and the pigment dispersion of latex, or the wet strength,

the water resistance and the adhesiveness of film ora,B-ethylenically unsaturated monomer by employing a sulfo ester of a-rnethylene carboxylic acid derivatives or monoalkylitaconoxypropanesulfonate derivatives as a polymerizable emulsifying agent, a homopolymer of the polymerizable emulsifyingagent, or a water-soluble copolymer or a liquid oligomer which is abundant in the polymerizable emulsifying agent is apt to be byproduced since such an polymerizable emulsifying agent is readily homopolymerized or copolymerized. In case of polymerizing anmB-ethylenically unsaturated monomer by employing a polymerizable emulsifying agent such as sodium lO-acrylamidestearate or sodium lo-acryloxystearate, a homopolymer of the polymerizable emulsifying agent is apt to be by-producedor the unreacted polymerizable emulsifying agent is apt to remain comparatively in large quantities since such a polymerizable emulsifying agent is readily homopolymerized but hardly copolymerized. These by-products and the residue are abundantly discharged together with a drainage because of their hard recovering. Therefore, such conventional polymerizable emulsifying agents also have the disadvantage in the point of environmental pollution though they are effective in improving properties as mentioned above.

Furthermore, there has been known as acrylonitrile copolymer for modacrylic fiber, especially the copolymer containing 30 to percent by weight of acrylonitrile, which is prepared by an aqueous emulsion polymerization process employing a usual emulsifying agent. However, such a copolymer contains a small amount of emulsifying agent even though water wash is completedas much as possible on industrial scale, and a modacrylic fiber prepared therefrom is inferior in heat stability and fastness to light due to the residual emulsifying agent. Therefore, commercial value of modacrylic fiber has been accepted with some discount in spite of its excellent properties such as flame resistance, high bulkiness, lusterness and hand touchness. For the purpose of decreasing the residual amount of emulsifying agent in the copolymer, the present inventors have carried out an emulsion polymerization by employing the aforementioned known polymerizable emulsifying agent. However, it has been found out that heat stability and fastness to light are not improved though the employed polymerizable emulsifying agent is copolymerized with acrylonitrile to be bonded chemically within the polymer molecule. Besides, under certain circumstances, softening temperature of the copolymer was lowered as a result of introducing a substituent group bulky in excess as a side-chain of the copolymer by means of copolymerizing an polymerizable emulsifying agent. As such examples, monoalkylitaconoxypropanesulfonate derivatives such as sodium monolaurylitaconoxypropanesulfonate are mentioned.

OBJECT OF THE INVENTION It is an object of the present invention to provide a novel polymerizable emulsifying agent.

Another object of the invention is to provide a novel polymerizable emulsifying agent capable of preventing a discharge of an environmental pollutant such as emulsifying agent, water-soluble polymeric material, water-soluble oligomer or oil-soluble oligomer in an aqueous emulsion polymerization of a,B-ethylenically unsaturated monomer.

Further object of the invention is to provide a novel polymerizable emulsifying agent which can give a polymer improved in properties such as transparency, heat stability, mechanical property, fastness to light, impact strength, heat flowability and processing property.

More further object of the invention is to provide a novel process for emulsion-polymerizing a,B-ethylenically unsaturated monomer employing the specific polymerizable emulsifying agent.

Still further object of the invention is to provide an improved aqueous emulsion polymerization process for a,B-ethylenically unsaturated monomer which does not discharge an environmental pollutant such as emulsifying agent, water-soluble polymeric material, watersoluble oligomer or oil-soluble oligomer in a step such as filtration and washing of polymer.

Still more further object of the invention is to provide a modacrylic fiber superior in heat stability and fastness to light.

These and other objects of the invention will become apparent from the description hereinafter.

DESCRIPTION OF THE INVENTION It has now been found that the above-mentioned objects are accomplished by a new polymerizable anionic emulsifying agent having the following general formula:

M is H, Li, Na, K or NH, and n is an integer of 2 to 4, inclusive.

FIGS. 1 to 9 are infrared spectrums of the first intermediate, the second intermediate and the polymerizable anionic emulsifying agent of the present invention.

The polymerizable anionic emulsifying agents of the present invention, sulfoalkylalkylmaleates, are prepared as follows:

The first intermediary monoalkylmaleate is prepared by reacting maleic anhydride and higher alcohol, and hydroxide of alkali metal or ammonium is reacted therewith to give the secondary intermediary alkali metal salt or ammonium salt of monoalkylmaleate. Then, by reacting the second intermediate and a sulfonating agent such as propanesultone, butanesultone or sodium 2-oxy-ethanesulfonate, end product of alkali salt or ammonium salt of sulfoalkyl-alkylmaleate is pre pared.

The first intermediary monoalkylmaleate is prepared in high yield of to percent by reacting equimolar amounts of maleic anhydride and higher alcohol at a reaction temperature of 50 to C., preferably 60 to 80C. for 2 to 3 hours in the absence of solvent. As a starting material, maleic anhydride is advantageously employed more than maleic acid by the following reason. In case of employing maleic acid, dialkylmaleate is apt to be by-produced since the reaction must be pro-.

ceeded at higher temperature in the presence of dehydrating agent such as mineral acid or aromatic sulfonic acid. In case of employing maleic anhydride, monoalkylmaleate is readily and quantitatively prepared at a moderate reaction temperature in the absence of dehydrating agent. Also as a higher alcohol, straightchain alcohol, branched alcohol, primaly alcohol, secondary alcohol and tertiary alcohol are employed irrespective of carbon number within the range of 6 to 22 carbon atoms. Further phenyl ethers such as phenyl ether of polyethylene glycol or phenyl ethers of polypropylene glycol may be employed as a starting material for the polymerizable anionic emulsifying agent. Also, a mixture of higher alcohols having carbon atoms substantially distributing in the range of 9 to 15 may be employed.

The secondary intermediary alkali metal salt or ammonium salt of monoalkylmaleate is prepared by adding powdery alkali metal hydroxide or a concentrated aqueous solution of alkali metal hydroxide, preferably 30 to 50 percent by weight aqueous solution, or an aqueous ammonia, preferably 30 to 50 percent by weight aqueous ammonia into monoalkylmaleate dissolved in organic solvent such as acetone, methanol or isopropanol, at a temperature of 20 to 60C. The hydroxide of alkali metal or ammonium is employed in an amount equimolar with monoalkylmaleate. In the above neutralizing reaction, the dispersibility of alkali is improved by employing the organic solvent as a reaction medium, and also the viscosity of the obtained dispersions of alkali metal salt or ammonium salt of monoalkylmaleate is lowered by employing the organic solvent. The organic solvent is preferably employed in an amount more than the amount of the employed alkali. In case of employing the organic solvent in such amount, there is no limitation to proceed the reaction. However, it is preferable to employ the organic solvent in an amount less than 20 times the amount of the employed alkali in order to distil off the solvent economically after the conclusion of the reaction. In case of employing the organic solvent in less amount, the agitation becomes difficult since the viscosity of the reaction mixture increases. As an organic solvent, it is necessary to employ one which does not react with the added alkali, and also does not form an azeotropic mixture with water produced by the neutralizing reaction between monoalkylmaleate and alkali. As an organic solvent, it is also necessary to employ one which does not react with the sulfonating agent such as sultones or sodium 2-oxy-ethanesulfonate in the next step, and moreover is readily recovered in the final step. By such reasons, acetone or methanol is suitably employed. Though isopropanol may also be employed, it is somewhat troublesome to separate completely it from the end product. Further, it is possible to neutralize monoalkylmaleate with aqueous solution of alkali metal hydroxide or aqueous ammonia and then to proceed the next sulfonation reaction in the aqueous medium. However, the ester value of the end product is lower than the case of the reaction in the organic solvent such as acetone since the sulfonating agent such as sultones ring-opens to the extent of 5 to 8 percent by weight. In case of employing the powdery alkali metal hydroxide, the neutralizing reaction is carried out by suspending the powder in the organic solvent having large polarity such as alcohol for fear that the ester bond is hydrolyzed during the neutralizing reaction of monoalkylmaleate. However, also in the aqueous alkaline solution or in the aqueous alkaline solution-organic solvent, the neutralizing reaction is proceeded in high yield, as shown in the following Table 1, by adjusting the reaction temperature below about 60C. Especially, in case of employing the acetone-water reaction medium or the methanol-water reaction medium, the end product is readily taken out and the organic solvent is also readily recovered since the second intermediate and the end product are well dissolved in the above reaction medium to give a uniform solution.

The end product, alkali metal salt or ammonium salt of sulfoalkyl-alkylmaleate, is prepared by reacting equimolar amounts of the second intermediate and the sulfonating agent such as propanesultone, butanesultone or sodium 2-oxy-cthanesulfonate, in the presence of the same organic solvent as employed in the preparation of the second intermediate at a temperature of 50 to 85C. for l to 4 hours. The end product is also prepared by reacting the first intermediary monoalkylmaleate and sodium isethionate in the presence of acidic catalyst. As the sulfonating agent, propanesultone is employed effectively more than butanesultone since the sulfonation is completed for a short time of 1.5 to 2 hours under a moderate condition due to its to its large reactivity. In case of employing sodium 2-oxyethanesulfonatc as a sulfonating agent, it is necessary to raise a reaction temperature and it is disadvantageous to employ them compared with sultones. The sulfonation by sodium 2-oxy-ethanesulfonate is completed for 8 to 10 hours at a moderate temperature of about C. by employing hydrogen chloride gas as a catalyst. Asan organic solvent employed in the reaction, there is effectively employed the solvent which does not react with sultones and has a large polarity and is readily recovered as aforementioned. The acetonewater reaction medium or the methanol-water reaction medium, which can make the reaction system uniform, is suitably employed.

The end product is a hygroscopic white solid which discolors at high temperature and does not indicate a sharp melting point. Completion of the reaction is confirmed by an ester value and an infrared spectrum of the product. As a result of sulfonation, while the absorption band at 1600 emf l due to carboxylate group which is characteristic absorption of alkali metal salt of monoalkylmaleate dicreases, the absorption band at 1730 cm. clue to ester group increases relatively and the absorption bands at 1200 cm." and 1050 cm. due to sulfonate emerge.

By the above-mentioned preparation method, sulfonalkyl-alkylmaleate is advantageously prepared in high yield in the absence of polymerization inhibitor such as hydroquinone without by-producing a homopolymer of maleic anhydride, monoalkylmaleate or sulfoalkylalkylmaleate since none of maleic anhydride, monoalkylmaleate and sulfoalkyl-alkylmaleate heatpolymerize independently and also catalytically polymerize independently under a normal preparation condition.

On the other hand, a conventional polymerizable anionic emulsifying agent such as sulfomethylene-amethyleneacrylate derivatives or monoalkylitaconoxypropanesulfonate derivatives can heat-polymerize independently. In case of preparing such an emulsifying agent, homopolymer of emulsifying agent is byproduced in large quantities and the yield of the desired product is extremely lowered. Further, in case of 'adding a large amount of heat-polymerization inhibitor into the reaction system for the purpose of raising the yield, a purification step by some means, that is, a removing step for the inhibitor is required after initiating the reaction. However, there is no purification method advantageous in industry and a great expense is incured by purification and further a purification efficiency is still insufficient.

The polymerizable anionic emulsifying agent of the invention is prepared in high purity since the reaction of maleic anhydride and higher alcohol proceeds quantitatively. On the contrary, the purity of a conventional polymerizable anionic emulsifying agent is low to some extent. For instance, in case of monoalkylitaconoxypropanesulfonate derivatives, dialkylitaconate is byproduced in the reaction of preparing monoalkylitaconate from itaconic acid and higher alcohol since a reaction catalyst is employed and a reaction equilibrium is shifted to the production system by dehydration.

Furthermore, maleic anhydride employed in the invention is cheaper than itaconic acid in commercial base. Therefore, there is advantage that the present polymerizable anionic emulsifying agent is prepared in high yield and high purity by the employment of the cheaper starting material.

HLB of the present sulfoalkyl-alkylmaleates, that is, hydrophilic-lipophilic balance of the emulsifying agent can be adjusted by adequately selecting (CH ),,SO M of hydrophilic sulfoalkyl group and R of lipophilic alkyl group/The structure of these substituent groups'is determined in accordance with the kind of monomer dispersed in the aqueous medium or the use of polymer since monomer is copolymerized together with the polymerizable anionic emulsifying agent[ The carbon number of the alkyl group R is suitably selected from the range of 6 to 22. In case the carbon number of the alkyl group R is less than 6 or more than 22, the emulsifying agent hardly shows a hydrophilic-lipophilic balance suitable for the emulsion polymerization.

The polymerizable anionic emulsifying-agent of the invention is added into an emulsion polymerization system to make emulsion polymerization proceed the same. as in a normal nonpolymerizable emulsifying agent. The polymerizable anionic emulsifying agent per se is also copolymerized with monomer and chemically bonded within a polymer molecule. Then, the residual amount of the emulsifyingagent is infinitesimal when the polymerization terminates. Therefore, it is possible to minimize the discharge of environmental pollutants which are discharged together with industrial wastes at the time of separating the polymer from latexthrough passing salting-out, filtraion and washing. In order to exhibit the effect preventing discharge of environmental pollutants most effectively, it is-necessary to employ the present polymerizable anionic emulsifying agent according to the following means. That is-to say, 93 to 99.5 percent by weight of a,B-ethylenically unsaturated monomer having solubility of not more than 10 percent by weight to water at 35C. and O to 2.percent by weight of a,B-ethylenically unsaturated monomer having a solubility of more than 10 percent by weight to water at 35C. must be copolymerized in the presence of 0.5 to 5 percent by weight of the present polymerizable anionic emulsifying agent in an aqueous medium.

The polymerizable anionic emulsifying agent in the invention has the similar emulsifying function to a conventional anionic emulsifying agent. The emulsifying agent forms micelle in the aqueous medium by which the monomer is solubilized and the resultant polymer particles are protected by chemically bonding so that a stablepolymer dispersion is provided. Table 2 shows the measuring results at C. of the relationship between the critical micelle concentration (CMC), which is one index of emulsifying function, and the surface tention at critical micelle concentration concerning the present polymerizable anionic emulsifying agent with reference of the result in case of sodium dodecylbenzenesulfonate which is one of well known emulsifying agent usually employed.

One of the principal advantages of sulfoalkylalkylmaleate of the present invention is that an environmentalp'ollution due' to the drainage can be prevented by the employment of the present polymerizable anionic emulsifying agent under the specific condition. Since sulfoalkyl-alkylmaleate d'o'es not copolymerize in excessand does not polymerize alone though it adequately copolymerizes with a,B-ethylenically unsaturated monomer, the water-soluble copolymerized material being abundant in the emulsifying agent or the homopolymer of the emulsifying agent is scarcely produced and the 'emu'lsifyi ng agent is chemically bonded to the polymer in high quantities. Therefore, the emulsifying agent employed in I the polymerization is scarcely discharged into the drainage as an unreacted emulsifying agent, a water-soluble polymeric material or a homopoly'rner" when the polymer is recovered from the polymer dispersion through salting out, filtration and washing.

Another principal advantagesofthe present invention is that the deterioration of quality of the shaped article prepared therefrom can be preyented, in case of manufacturing a shaped article such as film, fiber, or the like, from the polymer prepared by employing a conventional emulsifyingagent,the obtained shaped article is'inferior in transparency, heat stability, mechanical property, fastness to light, chemical resistance or water resistance since the employed emulsifying agent remains in the polymer with being adsorbed even if water washing of the polymer is carried out with a much amount of water. However,' according .to the present invention, the polymerizableanio nic emulsifying agent is chemically bonded within polymer molecule obtained by the copolymeri'zationfsince the emulsifying agent can adequately copolymerize with the a,B-ethylenically unsaturated monomer.

It is further a surprising thing that a modacrylic fiber prepared from a copolymer, in whichacrylonitrile is contained in the ratio of'30 to percent by weight and the-emulsifying-agent is copolymerized, is not only superior in heat stability and fastness to light but also well improved.

Table 3 shows a variation of viscosity of the aqueous solution of polymerizable emulsifying agent under the condition of polymerization, which is represented by the falling time measured with the elapse of time by Ostwalds viscosimeter at 50C. The polymerization of polymerizable emulsifying agents was carried out as follows:

As polymerizable emulsifying agents, sodiurn sulfopropylcetylmaleate whichis one of the present polymerizable imulsi'fying agentf sodium sulfopropyl-amethylacrylate and sodium monocetylitaconoxypropanesulfonate which are conventional polymerizable emulsifying agents and include 500 p.p. m. of hydroquinone are employed. Each polymerization vessel made by glass was'ch'arged with each 1 0 parts by weight of the above-mentioned emulsifying agents, respectively, and further charged with each parts by weight of deionized. water and each 0.5 part by weight of ammonium persulfate, respectively. After replacing air in the vessels sufficiently by nitrogen gas, the vessels were sealed and shaken for polymerization in a constant temperature bath maintained at 55C. for 36 hours. A part ofthe above-mentioned aqueous solutions was respectively taken out with the elapse of time and the vis- Table 3 Example Polymerizable Falling time by Ostwald's viscosimeter No. emulsifying agent hr. 12 hrs. 24 hrs. 36 hrs.

second A Sodium sulfopropyl-cetylmaleate 42.] 42.4 42.0 42.3

no variation B Sodium sulfopropyl-tx- 28 8 high viscosity. transparency. methylaerylate measurement is watersoluble impossible polymeric material C Sodium monocetylitaconoxylib 40.4 80.3 high viscosity.

propanesulfonate slight oily material turbidity exists cosity was measured at 50C.

In case of sodium sulfopropyl-cetylmaleate, there is no increasing of viscosity and it shows that sodium sulfopropylcetylmaleate is not polymerized alone. In case of sodium sulfopropyl-a-methylacrylate, the viscosity becomes considerably high at the time of passing 30 minutes from the initiation of polymerization. The aqueous solution is transparency, and it is clear that a watersoluble high polymer is produced. In case of sodium monocetylitaconoxypropanesulfonate, homopolymerization gradually proceeds after passing through a long induction period, and at the same time the oily material presumed as oligomer is produced. Further, it appears that the induction period varies slightly.

Table 4 shows the result of measurement of the residual amount of polymerizable emulsifying agent in filtrate and wash water and the chemical oxygen demand of the filtrate and the wash water. The polymerization and the measurement were carried out as follows: Each polymerization vessel was charged with each parts by weight of the polymerizable emulsifying agent employed in the above viscosity measurement. Further, 2000 parts by weight of deionized water, 190 parts by weight of aerylonitrile, 4 parts by weight of potassium persulfate and 1.5 parts by weight of sodium bisulfite were added to each vessel. After replacing air in the vessel by nitrogen gas, the vessels were sealed and shaken for polymerization on a constant temperature bath maintained at 40C. for 3 hours. After polymerization, the unreacted acrylonitrile was removed off by evaporation. and then salting-out and filtration were carried out. The washing of polymer was carried out by method, in which anionic emulsifying agent salt of Methylene Blue was extracted with chloroform and 'absorbance of extract was measured by a spectrophotometer and the amount was determined from a previously prepared calibration. curve. It is difficult to independently determine the amount of the unreacted polymerizable emulsifying agent and that of the polymerizable emulsifying agent bonded in the water-soluble polymer, and therefore, the figurs in Table 4 indicate the apparent amount of the polymerizable emulsifying agent including both emulsifying agents. In case of sodium sulfopropyl-eetylmaleate (Example D),the polymer was obtained in a form of latex. On the contrary,

in case of sodium sulfopropyl-a-methyl-acrylate (Example E) and sodium monocetylitaconoxypropanesulfonate (Example F), the polymers were obtained in a form of slurry. The amount of polymerizable emulsifying agent in filtrate and washwater in Example D was 0.28 part by weight. On the other hand, the amount in ExamplesE and F was approximately twice of that in Example D. The yields of polymer in three Examples are about the same, but it is assumed that the apparent amount of emulsifying agent in filtrate and wash water in Examples E and F is increased as a result of the formation of the watersoluble homopolyn'ier of emulsifying agent or the watersoluble copolymer since the emulsifying agents in Example E and F are apt to polymerize'compared with that in Example D. The value of chemical oxygen demand in Example D is small, while those in Examples E and F are large. it is assumed that the fact is caused by the presenee'of water-soluble polymerie materials. 7

Table 4 Example Polymerizable Polymer Yield of Amount of polymerizable COD of the mixture No. emulsifying dispersion polymer emulsifying agent of liltrate and agent present in the mixture wash water of filtrate and wash water 1 part by weight ppm.

D Sodium sulfopropyllatex 96.4 0.22% 14 eetylmaleate l. Sodium sullopropylslurry 95.2 l).6l 5i a-methylacrylate l- Sodium monoeetylitaeoslurry 95.6 0.58 41 mmypropanesulfonate 8000 parts by weight of water. The filtrate and the wash water were combined and the chemical oxygen demand was measured by a potassium permanganate-method at C. for 30 minutes in accordance with the provision of .115 K (H02. The residual amount of polymerizable emulsifying agent was determined by a absorptiometric For the purpose of preventing the discharge of environmental pollutants, the amount of the polymerizable emulsifying agent may vary according to a kind of monomer or a use of polymer. Usually, the emulsifying agent is employed in the ratio of 0.5 to 5 percent by weight to the total amount of polymerizable materials.

In case the amount employed is less than 0.5 percent by weight, the stable polymer dispersion is hardly obtained. In case the amount employed is more than percent by weight, the unreacted polymerizable emulsifying agent increases so that the COD value of drainage substantially becomes large.

According to the present invention, a,B-ethylenically unsaturated monomer applicable to the process employing the present polymerizable emulsifying agent must be one which has at least one unsaturated bond capable of subjecting to addition polymerization and has a solubility of not more than percent by weight to water at 35C. Examples of the a, B-ethylenically unsaturated monomer having a solubility of not more than 10 percent by weight to water at 35C. are ethylene, vinyl cyanides such as acrylonitrile, methacrylonitrile and vinylidene cyanide, styrene and derivatives thereof such as a-methylstyrene, p-methylstyre'ne or pmethoxystyrene, acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate and 2- ethylhexyl acrylate, methacrylic esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate and 2-ethylhexyl methacrylate, halogen-containing monomers such as a-chloromethyl'acrylate, a-chloroethyl acrylate, vinyl chloride, vinylidene chloride, vinyl bromide, vinylidene bromide, vinyl fluoride and vinylidene fluoride, vinyl esters such as vinyl acetate, vinyl propionate or vinyl stearate, .vinylpyridines such as 2- vinylpyridine, 4-vinylpyridine and 2'-methyl'-5- vinylpyridine, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, dodecyl vinyl ether and cetyl vinyl ether, N-vinylcarbazole, vinylfuran, isoprene, chloroprene, isobutylene, 1,3-butadiene, and the like. Such an a,B-ethylenically unsaturated monomer is suitably employed alone or together with a,fi-ethylenically unsaturated monomer having a solubility of more than 10 percent by weight to water at 35C., in an amount of 93 to 99.5 percent by weight to the total amount of polymerizable materials.

In case 0:,B-ethylenically unsaturated monomer having a solubility of more than 10 percent by weight to water at 35C. is copolymerized, it is suitably employed in an amount not more than 2 percent by weight to the total :amount of polymerizable materials. Examples of the a,B-ethylenically unsaturated monomer having a solubility of more than 10 percent by weight are acryl amide, N-vinylpyrrolidone, acrylic acid, methacrylic acid, allyl sulfonic acid, methallyl sulfonic acid, pstyrene sulfonic acid, and alkali salts thereof. In case of employing such a monomer in large amount, the copolymer with polymerizable emulsifying agent, which is produced as a by-product, is apt to become watersoluble, and such a watersoluble material is discharged into drainage in comparatively high ratio when the polymer is recovered from the polymer dispersion through salting-out, filtration and washing. For the purpose of preventing the discharge of water-soluble material causing an environmental pollution, the abovementioned monomer having a strong hydrophilic property is preferably employed in an amount of not more than 2 percent by weight to the total amount of polymerizable materials although the amount may also depend on the amount of the polymerizable emulsifying agent existing in the system.

Table 5 shows the results of the polymerization according to the process of the invention. Examples G, H

v and I illustrate the copolymerization of monomer having a solubility of not more than 10 percent by weight to water at 35C. and the specific polymerizable anionic emulsifying agent. Examples K, L, N and O illustrate the copolymerization of monomer having a solubility of not more than l0 percent by weight to water at 35C. monomer having a solubility of more than l0 percent by weight to water at 35C. and the specific polymerizable anionic emulsifying agent in which monomer having a solubility of more than 10 percent by weight to water at 35C. is employed in excess, and also Examples J and M illustrate the copolymerization of the above three polymerizable materials in which monomer having a solubility of more than 10 percent by weight to water at C. is employed in the amount within the above-mentioned range. The copolymerization was carried out as follows: A polymerization V vessel was charged with 700 ml. of deionized water and 100 g. of mixture of polymerizable materials. After replacing air in the vessel by nitrogen gas, 3 g. of ammonium persulfate and l g. of sodium bisulfite were added to the vessel and the copolymerization was carried out at a temperature of 50C. for 5 hours. After copolymerization was terminated, the pressure within the'vessel was reduced with maintaining a temperature of 50C. so that the residual volatile monomer is removed off by evaporation. Then, to the polymer dispersion was added an aqueous solution of sodium sulfate to salt out the copolymer. After filtration of the copolymer dispersion, the copolymer was washed with 6 liters of water and the fitrate and the wash water were combined.

The amount of emulsifying agent in the combined water consisting of filtrate and wash water was determined by an absorptiometric method, and the chemical oxygen demand was determined by a potassium permanganate-method at 100C. for 30 minutes in accordance with the provision of HS K 0102.

Table 5 Monomer composition Yield Amount of COD of the of emulsifying mixture of Example Monomer having a Monomer having 21 Sodium sull'opolymer agent present filtrate No. solubility of not solubility of more propyl-eetylin the mixture and wash more than l0 7: than H) '71 maleate of filtrate water and wash water g. g. g. p.p.m.

Aerylonitrile 4 93.2 0.21 17 )6 Methyl methaerylate h 4 89.5 0.24 21 )(i l Vinyl acetate A 4 93.6 0,18 l) 96 J Aerylonitrile Acrylamide 4 92.4 0.30 3| 9. l K Aerylonitrile Aerylamide 4 90.] 0,68 I02 )2 4 l. Aerylonitrile Acrylic acid 4 94.0 0.71 )8 )2 4 M Methyl methacrylate 90.6 0.32 33 Methaerylic acid 4 Table Continued Monomer composition Yield Amount of COD of the olemulsifying mixture ol Example Monomer having a Monomer having a Sodium sullopolymer agent present filtrate 7 No. solubility of not solubility of more propylwetylin the mixture and wash more than H) k than H) "1' malcatc of filtrate 'LICI' and wash water E" 7 PP- N Methyl methacrylatc Mcthucrylic acid 4 9i .3 (L67 )4 2 4 Vinyl acetate N-vinylpyrrolidone 4 92.8 0.65 l l9 In case of Examples G, H and l, the residual amount of the employed emulsifying agent in the mixture of filtrate and wash water is a little and it shows that the emulsifying agent is chemically bonded in high yield in the recovered polymer. The chemical oxygen demand of the mixture of filtrate and wash water is also low. The chemical oxygen demand caused by the employed monomer, that is, acrylonitrile, methyl methacrylate or vinyl acetate is a few p.p.m. since the unreacted monomer is substantially removed off by evaporation under a reduced pressure. In case of Examples K, L, N and O, the residual amount of the employed emulsifying agent in the mixture of filtrate and wash water is comparatively much. The chemical oxygen demand of the mixture of filtrate and wash water'is extremely high. It is caused by the water-soluble polymeric material and monomer, that is, acrylamide, acrylic acid, methacrylic acid or N-vinylpyrrolidone, which is readily soluble in water and is hardly removed off by evaporation under a reduced pressure. In case of Examples J and M, the residual amount of the employed emulsifying agent in the mixture of filtrate and wash water is a little, and the chemical oxygen demand is also comparatively low. In order to satisfy the condition that emulsifying agent and water-soluble polymeric material causing an environmental pollution are not discharged in filtering and washing drainage, it is essential that a,B-etl1ylenically unsaturated monomer to be copolymerized with the present polymerizable emulsifying agent must have a solubility of not more than 10 percent by weight to water at 35C. and, in case a,B-ethylenically unsaturated monomer having a solubility of more than 10 percent by weight to water at 35C. is further copolymerized, the amount must be not more than 2 percent by weight to the total amount of the employed polymerizable materials.

The aqueous emulsion polymerization can be carried out in accordance with a conventional process. For instance, the present polymerizable emulsifying agent is added together with a,B-ethylenically unsaturated monomer into the aqueous medium. After addition of a known polymerization initiator, the polymerizable materials are usually polymerized at a temperature of 30 to 100C. with agitation. In that case, of course, it

is preferable to previously remove materials interfering the polymerization such as oxygen by means of evacuation or replacement with inert gas such as nitrogen gas. The above-mentioned aqueous medium means a mixture of water and a small amount of water-miscible or- ;ganic solvent such as alcohols or ketones. According to the process of the invention, a small amount of usual emulsifying agent may be added in the aqueous medium in addition to the present polymerizable emulsifying agent. In case of daring to add a usual emulsifying agent, however, it is preferably employed in less amount than that employed in a conventional emulsion polymerization process since the polymer dispersion I being substantially stable can be obtained only by the present polymerizable emulsifying agent.

As a polymerization initiator, any of water-soluble polymerization initiators are applicable. Examples of the water-soluble polymerization initiator are inorganic peroxides such as hydrogen peroxide, potassium persulfate or ammonium persulfate, organic peroxide such as acetyl peroxide, tert-butyl hydroperoxide, tert-butyl perisobutyrate, tert-butyl peroxypivalate. Also the redox system in which the above-mentioned peroxide is employed together with, for instance, sodium sulfite, reductive sulfoxylic compounds such as formaldehydesodium sulfoxylate dihydrate, or ferrous sulfate, may be employed. In accordance with a durability of activity of initiator or an. apparent reaction rate, of a mixture of polymerizable materials, the polymerization initiator may be introduced by such a way as introducing the initiator at once before initiating the polymerization, periodically introducing a part of initiator or a part of noe or both ingredients of a redox system through polymerization, or continuously introducing the initiator in the course of polymerization.

In accordance with the reactivity of monomer or the composition of polymer, afi-ethylenically unsaturated monomer and the present polymerizable emulsifying agent may be introduced into the polymerizable materials at once at the time of polymerization, periodically introducing a part of the polymerizable materials through polymerization or continuously introducing a part of the polymerizable materials in the course of polymerization. Y i

The polymerizable anionic emulsifying agent of the invention is also applicable to the .graftcopolymerization in the presence of polymer latex.

The polymer dispersion obtained by the process employing the present polymerizable emulsifying agent shows an excellent stability without producing coagula or scale on polymerization vessel in spite of that a usual emulsifying agent is employed in a slight amount or is not employed at all.

By employing the present emulsifying agent, the environmental pollutants such as emulsifying agent or water-soluble polymeric material or water-soluble or oil-soluble oligomer are not discharged at the time of filtering polymer from aqueous medium and washing when a polymer employed as a starting material for shaped article such as synthetic resin, synthetic fiber or synthetic rubber is manufactured. Further, in case of processing the polymer obtained by the instant process to a shaped article such as film, fiber, or the like,the polymer can provide a shaped articlesuperior in transparency, heat stability, mechanical property, fastness to light, impact strength, ,heat flowability and processing property since the emulsifying agent is chemically bonded within the polymer molecule. Especially, in case the polymerizable emulsifying agent of the invention is chemically bonded within molecule of acrylonitrile copolymer having 30 to percent by weight of acrylonitrile content as a result of emulsion polymerization employing the present polymerizable emulsifying agent, a modacrylic fiber prepared therefrom can be well improved in heat stability and fastness to light.

In general, a modacrylic fiber has been prepared from copolymer comprising 30 to 80 percent by weight of acrylonitrile, 70 to 20 percent by weight of vinyl chloride or vinylidene chloride and to by weight of another comonomer as a modifier. However, such a modacrylic fiber has the disadvantage that heat stabil ity and fastness to light are not appreciably excellent. On the contrary, it has been found that heat stability and fastness to light are improved by copolymerizing the present polymerizable anionic emulsifying agent. Though the amount of the polymerizable emulsifying agent employed in order to improve heat stability and fastness to light is not limited particularly if the amount is not less than 0.5 percent by weight to the total amount of polymerizable materials, it is suitably employed in the amount of 0.5 to 5 percent by weight to the total amount of polymerizable materials under the consideration that the polymerizable emulsifying agent also functions as a modifier for maintaining luster in boiling water and dyeing ability. In case the amount is more than 5 percent by weight, modacrylic fiber is apt to deluster in boiling water and uneven dyeing is apt to occur since a hydrophilic property and an affinity to dyestuff of the modacrylic fiber become too large.

T It is not clear at the present time why heat stability and fastness to light of the modacrylic fiber are improved" by copolymerizing the present polymerizable emulsifying agent with monomer. However, it may be considered that Zipper Reaction of the conjugated double bonds generated by dehydrochlorination caused by heating of modacrylic fiber is stopped at the neighboring two carbon atoms in the maleic acid unit of the polymerizable emulsifying agent, which takes part in the main chain of copolymer, since the carboxylate groups are bonded to the above-mentioned carbon atoms. Or again, it may be considered that the dehydrochlorination of modacrylic fiber activated by photo energy is prevented by absorption of photo energy by maleic acid derivative unit. In that case, it is clear that the above-mentioned properties are not improved by the reason why the residual amount of the polymerizable emulsifying agent adsorbed physically in produced polymer without chemically bonding in the polymer is least. The heat stability and fastness to light of a modacrylic fiber prepared by employing a conventional polymerizable emulsifying agent is not improved in spite of the least amount of emulsifying agent remaining in the fiber.

For the purpose of improving the heat stability and fastness to light of the modacrylic fiber, the fiber is prepared by employing the polymerizable anionic emulsifying agent ofthe invention through passing the following steps. Acrylonitrile and vinyl chloride or vinylidene chloride are emulsion-polymerized in the presence of thc polymerizable emulsifying agent in an aqueous medium to give an aqueous latex or aqueous slurry containing the acrylonitrile copolymer. In that case, a small amount of another a,B-ethylenically unsaturated monomer may be copolymerizcd therewith as occasion demands. Then, the polymer powder is taken out from the obtained aqueous latex or the aqueous slurry through salting-out, filtration, washing and drying. The polymer powder is dissolved in an organic solvent to prepare a spinning solution. As occasion demands, there may be added into the spinning solution a heat stabilizer, an antistatic agent, a fluorescent agent, rust inhibitor, a delustering agent and other additives. Then the spinning solution is introduced into a coagulating bath, which consists of the same organic solvent as employed in the preparation of the spinning solution and water. through a spinning nozzle. The coagulated filament is drawn in the second coagulating bath. Thus obtained filament is introduced into a washing bath to remove the organic solvent, and successively introduced into a primary-oil bath to raise filament separatability of fiber. Then the obtained filament is dried and heatdrawn in order to provide an excellent mechanical property to the fiber. Further, an annealing for providing dimensional stability under tension or non-tension and a second-oil treatment for' improving spinning property are carried out in order. From thus obtained fiber, a modacrylic staple is prepared through crimping and cutting. As occasion demands, the abovementioned annealing maybe carried out in final step.

The polymerization step is the most important step to improve the heat stability and the fastness to light. In order to make the effect exert most favorably, the polymerizable emulsifying agent of the invention must be employed in an amount of not less than 0.5 percent by weight to the total amount of the polymerizable materials. In the presence of the present polymerizable emulsifying agent, 30 to percent by weight, preferably 35 to 75 percent by weight of acrylonitrile, 69.5 to 19.5 percent by weight, preferably 64.5 to 29.5 percent by weight of vinyl chloride and/or vinylidene chloride and O to 3 percent by weight of another comonomer are copolymerized. As the above another comonomer, there may be employed the aforementioned 0t,B-ethylenically unsaturated monomer having a solubility of more than 10 percent by weight to water at 35C. It is desirable that the produced polymer composition is uniform all through the polymerization. For the purpose of making the polymer composition uniform, the ratio of polymerizable emulsifying agent, acrylonitrile, vinyl chloride or vinylidene chloride and another comonomer in the polymerization system is maintained at the fixed ratio through the polymerization in accordance with each copolymerization reactivity ratio. For instance, since acrylonitrile and sodium sulfopropyl-tridecylmaleate are more reactive than vinyl chloride, a copolymer containing 50 percent by weight of acrylonitrile, 2 percent by weight of sodium sulfopropyl-tridecylmaleate and 48 percent by weight of vinyl chloride is uniformly prepared as follows:

At first, 10 parts by weight of acrylonitrile, 0.3 part by weight of sodium sulfopropyl-tridecylmaleate and parts by weight of vinyl chloride are mixed in an aqueous medium to prepare an emulsion. Then, a monom er mixture consisting of 52 parts by .weight of acrylonitrile and 1.7 parts by weight of sodium sulfopropyltridecylmalcate is continuously introduced into the polymerization system till the polymer yield is reached to 1 IO parts by weight. Such a mixing ratio is determined by the well known theoretical equation for terpolymer. In case of copolymerizing acrylonitrile, vinylidene chloride and the polymerizable emulsifying agent, the mixing ratio thereof is also determined by the theoretical equation for terpolymer. However, since their copolymerization reactivity ratios are similar to each other, a copolymer having a uniform composition is obthereof. A concentration of acrylic eopolymer in thespinning solution is normally to 30 percent by weight. The spun fiber is drawn 1.3 to 5.0 times to the original in the coagulating bath. The drying and heatdrawing are carried out at a temperature of 90 to 140C., and the fiber is usually drawn 2m 4; times to the fiber prior to the heat-drawing. The annealing is carried out at a temperature of 130 to 160C. The

spun fiber is eventually drawn 4 to 12 times to the original. Another known spinning arts also may be applied to the preparation of modacrylic fiber. 7

The heat stability and the fastness to light of the modacrylic fiber are determined by the following method. The heat stability of the fiber is determined by comparing degree of whiteness between the heat drawn fiber and the fiber annealed at 150C. for 10 minutes. The less the difference between them, the better the heat stability. The index of the degree of whiteness is represented by Hunter Yellowness calculated by the follow ing equation.

A/us 8/118 1 Hunter Yellowness (H.Y.) (I.

A: Reflectivity of the fiber surface by light of about 600 ma. G: Reflectivity of the fiber surface by light of about 550 mp. v I B: Reflectivity of the fiber surface by light of about 450 mp.. (MgO standard white surface is employed.) V The reflection is measured by photoelectric photometer SEP-H type made by Nippon Seimitsu Kogaku Kabushiki Kaisha. The less Hunter Yellowness, the better the degree of whiteness of the fiber. interrelation between the above index and a judgement by the naked eye is close. The fastncss to light is measured by fade-o- .meter at a temperature of 40 i2C. for 320 hours, and

determined by the degree of fading'and the retention to tensile strength of the fiber. The degree of fading is estimated in accordance with the following classification.

Class Exposing time till fading occurs (hours) -Continued Exposing time till fading The retention to tensile strength is calculated by the following equation.

I ganic solvent and printability are improved when the polymer is employed as a powdery .paint, and water resistance and miscibility with pigment are improved when the. polymer dispersion is employed as an aqueouspaint.

Theinventionis more particularlydescribed and explained by means of the following illustrative Exam- .ples, in which;all parts and percentages are by. weight except as noted i 1 EXAMPLE 1 Sodium:sulfopropyl-laurylrnaleate 1'-1. Preparation of monolaurylmaleatez' A reactor equipped with an agitator and a reflux condenser was charged with 186.1 g. (1.0 mole) of n-lauryl alcohol and 98.1 g. (1.0 mole) of maleic anhydride. The mixture was heated at a temperature of 809C. for 2 hours with agitation, and ther eafter was allowed to cool. The obtained white solid was recrystallized from hexane to give 270.2 g. of white crystal having a melting point of,56.3 to 569C. and an ester value, of 195 (KOH mg./g.). The yield was percent.

1-2. Preparation of sodium monolaurylmaleate:

To 1 422 g. (0.5 mole of the product obtained in the above item 1-1 was added g. ofacetohe. After agitating the mixture at a temperature of 30 to 50C. to give a uniform solution, 50 percent aqueous solution of sodium hydroxide eontaining 20 g. of.sodium hydroxide was gradually added dropwise to the solution with agitation and with maintaining the reaction temperature at below 58 to 608C followed by further agitation for 30 minutes. The reaction mixture was cooled to a temperature 'of-SfC. and the obtained white suspension was filtered and washed with cold acetone to give 148.6 g. 'or a white solid having a melting point of 107.s to 111.2C. and an ester value of 182((KOH mg./g.). The yield was 97 percent. 7 v 7 1-3. Preparation of sodium sulfopropyllaurylmaleate: To 76.6 g. (0.25 mole) of the productobtained in the above item l-2 were added 50 g. of acetone and 30.5

g. (0.25 mole) of propanesultone. The reaction mixture EXAMPLE 2 Sodium sulfopropyl-hexylrnaleate" 2-1. Preparation of sodium monohexylmaleate:

A mixture consisting of 98.1 g. (1.0 mole) of maleic anhydride and 102.1 g. (1.0 mole) ofn-h'exanol was agitated for 2 hours at a temperature of 80C. by the same manner as in Example 1, item 1-1. To the obtained uniform, clear liquid of monohexylmaleate (ester value: 275) wasadded 200 g. of acetone, and a'n'eutralizing reaction was carried outwith addingdropwise 50 percent aqueous solution of sodium hydroxide by the same' manner as in Example 1, item 1 2. Then, the reaction mixture was cooled; The precipitated white solid was filtered and washed with cold acetone to give 21 1 g. of hygroscopic white solid having a melting point of'49 to 52C. and an'ester value of 249. The yield of sodium monohexylmaleate was 95 percent.- i 2-2. Preparation of sodium sulfopropyl-hexylrnaleate:

The same procedure as in Example 1, item 1-3w as repeated'except that'55.6 g. of the productobtai'ried in the above item 2-1 was employed. The 'obtained hygroscopic white solid was dried to'giv'e*84.4 of sodium sulfopropyl-hexylmaleate having an ester value of 320. The yield was 98 percent.

Infrared spectrums of monohexylmaleate, sodium monohexylmaleate and sodium sulfopropylhexylmaleate were shown in FIGS. 4 to ,6, respectively.

EXAMPLE 3 g Sodium sulfopropyl-cetylmaleate 3-1. Preparation of monocetylmaleate: I j

A reactor equipped with an agitator and a reflux condenser was charged with 2422 g. (1.0 mole) of n-cetyl alcohol' and 98.1 g. (1.0 mole) of maleic anhydride. The mixture was heated at a temperature of 80C. for 2 hours with ag itation and thereafter was allowed to cool. The product was recrystallized from hexane to give 326.7 g. of white solid having a melting point of 77.4 to 790C. and e'ster'value of 160. The yield was 96 percent. I 3-2. Prepara tion of sodium mon'ocetylmaleate:

To 170.2 g. (0.5 mole) of the product obtained in the above'item 3-1 was added 100 g. of acetone, and'the mixture was agitated. Then, the 'neutralizing reaction was carried out by adding dropwise 30 percent aqueous solution of sodium hydroxide containing 2 g. of sodium hydroxide to the obtained uniform solution to give 87.9 g. of whitelsolid havingla melting point of 113.9 m 1|5.sc. and an estervalue or 14s. The yield of sodium monocetylmaleate was 97 percent. 3-3. Preparation of sodium sulfopropyl-cetylmaleate:

To 90.6 g. (0.25mole) of the product obtained in the above item 3-2 was added 50 g. of acetone. After agitating the mixture at 55 to 60C 30.5 g. (0.25mole) of propanesultone was further added and thus obtained mixture was refluxed for 2 hours with heating. Then, the mixture was cooled to a room temperature and the monocetylmaleate precipitated white solid was washed with cold acetone. Thus obtained hygroscopic white solid was dried under vacuum to give. 119.9 g. of, sodium sulfopropylcetylmaleate having an ester value of 228. The yield was 99 percent. Q

ln frared spectrums of monocetylmaleate, sodium and sodium sulfopropylcetylmaleatewere shown in FIGS. 7 to 9, respectively.

' EXAMPLE 4 Sodium sulfopropyl-cetylmaleate A reactor-equipped with'an agitator and a reflux condenser was'ch'argedwith 242.2 g. (1.0 mole) of n-cetyl alcohol and '23 g. (1.0 mole) of metallic sodiumuThe rnixturewas heated at a temperature of-l20C. for 5 hours with agitation to prepare sodium cetylate. Then, the obtained sodium cetylate was gradually added with agitation to a solution which was obtained by dissolving 98.1 (1.0 mole) of rnaleicanhydride in 500 g. of benzeneat a'temperature of 60C.'Aft er addition, the mixture was further agitated at a temperature of 80C. for

2 hours. The' reacted mixture was cooled, and the obtained w'hi'te precipitatewasafiltered and dried under vacuum to give 261.4 g. of sodium mono'cetylmaleate havin g a melting point of 115.3 to 115.8C. and an ester value of 150. The yield was 97 percent.

Then, from thus obtained sodium monocetylmaleate, sodium sulfopropyl-cetylmaleate 'was'prepared by the same manner'asiri Example 3, item 3-3. I

EXAMPLES e f Sodium sulfopropyl-laurylrnaleate To 71.1 g. (0. 25 mole) of monolaurylmaleate obtained-by the procedure of Example ,1, item l-l was added 50 g. of isopropanol. After agitation, a suspension containing 10 g. (0.25 mole) of sodium hydroxide in 250 g. of isopropanol was added to the mixture and thus obtained mixture was refluxed at ,a temperature of C. for 1.5 hours with agitation. Then, the reacted mixture was added with 30.5 g. (0.25 mole) of propanesultone and was further agitated at a temperature of 80C. for 2 hours. From the obtained white gelati- 1no'us liquid, isopropanol was distilled off under reduced temperature below 55C. Then the mixture was agitated at a temperature of 40C. for 0.5 hour, and thereto 30.5 g. (0.25 mole) of propanesultone was added. The reaction mixture was agitatedat a temperature of 60C. for 2 hours, and after reaction, water was distilled off under a reduced pressure from the obtained white gelatinous product. The vacuum drying was carried out to give l05.0 g. of hygroscopic white solid of sodium sulfopropyl-laurylmaleate having an' ester value of 256. The yield was 98 percent.

.2 EXAMPLE 7 Sodium sulfoethyl-laurylmaleate To 71.1 g. (0.25 mole) of monolaurylmaleate obtained by the procedure of Example 1, item 1-1 was added 40.6 g. (0.25 mole) of sodium 2-oxyethanesulfonate. The mixture was agitated at a temperature of 220C. for 1.5 to 2 hours with removing water produced during the reaction under a reduced pressure of 15 to 300 mmHg. Then the mixture was cooled to a room temperature, and 82.9 g. of white waxy sodium sulfoethyl-laurylmaleate having an ester value of 210 was obtained. The yield was 80 percent. The melting point was indefinite since the product had a thermal decomposing property.

EXAMPLE 8 Sodium sulfoethyl-laurylmaleate The mixture of 71.1 g. (0.25 mole) of monolaurylmaleate obtained by the procedure of Example 1, item l-l and 40.6 g. (0.25 mole) of sodium 2-oxyethanesulfonate was agiated at a temperature for about 8 to 10 hours with passinghydrogen chloride gas till the obtained reaction product became soluble in water. To the reaction product were added 200 g. of ice water and 100 g. of saturated solution of sodium chloride. After allowing it to stand, the upper layer was separated off to give the under layer containing sulfoethyllaurylmaleate. The under layer was neutralized by vl percent aqueous solution of sodium hydroxide, then water wasa removed off under reduced pressure to give 80.8 g. of white waxy sodium sulfoethyl-laurylmaleate having an ester value of 230. The yield was 78 percent.

EXAMPLE 9 Sodium sulfobutyl-laurylmaleate To acetone was added 76.6 g. 0.25 mole) of sodium monolaurylmaleate obtained by the procedure of Example l, item 1-2, and dissolved. Then, 34.1 g. (0.25 mole) of butanesultone was added to the solution, and the mixture was agitated at a temperature of 60C. for 3 hours. The reacted mixture was cooled to a room temperature and the precipitated white gelatinous solid was washed with cold acetone. The obtained hygroscopic white solid was dried under vacuum to give 105.2 g. of sodium sulfobutyl-laurylmaleate havingan ester value of 240. The yield was 95 percent.

EXAMPLES 10 TO AND COMPARATIVE EXAMPLES 1 TO 6 Practical Example (1) of the polymerization process for preventing environmental pollutions A reactor equipped with an agitator and a reflux condenser was charged with 200 ml. of toluene, 242 g. of cetyl alcohol and 5 ml. of 5 percent aqueous solution of sulfuric acid. After substantial agitation, 98 g. of maleic anhydride was added and the mixture was refluxed at a temperature of 105 to 110C. for 4 hours. Then the mixture was gradually cooled to a temperature of 0C. and the precipitated white crystal was filtered with suction. The crystal was recrystalized from the mixed solvent of benzene-ligroin to give about 326 g. of monocetyl maleate. Another reactor equipped with an agitator and a reflux condenser was charged with 150 ml. of isopropyl alcohol and 300 g. of monocethyl maleate. The reactor was further charged with a suspension in which 40 g. of sodium hydroxide is suspended in 350 ml. of isopropyl alcohol with agitation and the refluxing was started with heating. Then the mixed solution of ml. of isopropyl alcohol and 108 g. of propanesultone was gradually added and the mixture was refluxed at a temperature of 78 to 82C. for 4 hours with agitation. After the reaction was terminated, isopropyl alcohol was removed off by reducing the pressure with heating. Finally the resultant was dried at a temperature of to 110C. to give about 417 g. of a white waxy material of sodium sulfo'propylcetyl maleate.

Thus obtained sodium sulfopropylcetyl maleate was employed as a polymerizable emulsifying agent and an aqueous emulsion polymerization was carried out as follows: A pressure polymerization vessel was charged with 560 m1. of deionized water, 3 g. of sodium sulfite, 0.002 g. of ferrous sulfate and 100 g. of monomer mixture'as shown in Table 6. With agitating the mixture and elevating the temperature 0.5 g. of ammonium persulfate was added to the mixture and the polymerization was carried out at a temperature of 50C. Am-

monium persulfate was added in an amount of 0.2 g. at intervals of an hour. In each Example, the polymerization was continued for about 5 to 8 hours till the yield became more than 90 percent. After the polymerization was terminated, the vessel was evacuated with maintaining the temperature at 50C. so that the unreacted volatile monomer was removed off from the obtained polymer dispersion. Then 100 ml. of a 10 percent aqueous solution of sodium sulfate was added to the polymer dispersion to salt out the polymer. After heating, the polymerdispersion was filtered and the polymer was sufficiently washed with 3.5 liters of water.

The filtrate and the wash water were combined, and the amount of the emulsifying agent present in the combined water was determined by a absorptiometric method and the chemical oxygen demand of the combined water was determined by a potassium permanga nate-method at 100C. for 30 minutes in accordance with the provision of HS K 0102-1971. The term transparency of film refers to the percent transmission which is determined by measuring the ratio oflight transmitted through the film having a thickness of 0.3 mm. prepared from a 15 percent tetrahydrofuranmethyl ethyl ketone solution of the polymer under the prescribed condition. Further, the term heat stability of film" refers to the time required until the color of the above-mentioned film turns to light brown when the film is heated at a temperature of C. in Geers oven.

The results were shown in Table 6.

Table 6 Monomer composition Emulsifving agent Yield of Amount of COD of Property of the film polymer emulsithe Ex. Vinyl Vinyl N-vinyl- Sodium Sodium Sodium fying agent mixture Truns Heat No. chloride acetate pyrrolisulfo dodceyllauryl present in of filparency stability done propylbenzene sulfate the mixture tratc cetylsull'onatc of filtrate and maleate and wash wash water water '71 /1 g. g. p.p.m. "/1 min.

10 89.3 10 0.7 92.0 (1.04 6 92 35 11 88 10 2 93.3 0.09 11 93 40 12 86 10 4 93.6 (1.1 8 20 95 45 13 87 1() l 2 94.3 0.13 18 94 40 14 86 ll) 2 2 94.5 0.18 21 94 40 15 85 l() 1 4 91.9 0.22 23 95 45 Com. large Ex. quantity 1 89.7 10 (1.3 of coagula 86 25 2 82 ll) 8 92.8 0.56 64 91 40 3 84 ll) 4 2 92.0 0.35 61 92 35 4 82 1(1 4 4 93.5 0.59 97 92 15 90 2 92.6 1.89 52 82 25 6 90 ll) 2 91.7 1.92 85 84 25 As is clear from Table 6, the amount of polymerizable emulsifying agent in the mixture of filtrate and wash water in Examples 10 to was a little and the chemical oxygen demand was also low. Therefore, the filtrate and the wash water can be discharged as an industrial waste without any treatment. Also, the transparency and the heat stability of the film were excellent. On the other hand, in case of Comparative Example l, the uniform polymer dispersion was not obtained as a result of the formation of a large amount of coagula due to the lack of the polymerizable emulsifying agent. In case of Comparative Example 2, the unreacted polymerizable emulsifying agent was abundantly present in the filtrate and the wash water and the chemical oxygen demand was also high since the polymerizable emulsifying agent was employed in excess. In case of Comparative Examples 3 and 4, the water-soluble polymeric material was by-produced since N- vinylpyrrolidone being readily soluble in water was employed in large quantities. As a result, the amount of polymerizable emulsifying agent in the mixture of filtrate and wash water and the chemical oxygen demand are high, and the filtrate and the wash water can not be discharged as an industrial waste without any treatment. Comparative Examples 5 and 6 show the polymerization employing a conventional non-polymerizable emulsifying agent. A large portion of the employed emulsifying agent was present in the filtrate and the wash water, and the chemical oxygen demand was also high. Further, the transparency and the heat stability of the film were inferior. It is assumed that the inferiority is caused by the emulsifying agent adsorbed into the polymer.

EXAMPLES 16 TO 21 AND COMPARATIVE EXAMPLES 7 TO 12 Practical Example (11) of the polymerization process for preventing environmental pollutions Sodium sulfopropyl-Z-ethylhexylmaleate was prepared by the same manner as in Example 1 and was employed as a polymerizable emulsifying agent.

Then the amount of polymerizable emulsifying agent and the chemical oxygen demand were measured by the same manner as in Example 10.

Further, the processing property of the polymer was evaluated by a mixing roll for rubber at a temperature of 40 to 60C. The processing property is determined by thedegree of winding to roll and the condition of polymer according to the following criterion.

A: smooth winding on roll and extremely easy mixing B: winding on roll without separating from roll and easy mixing but a little bad eating into roll C: easy separation from roll and not easy mixing As Comparative Examples 7 to 12, the same procedures as in the above Examples were repeated except that sodium dodecylbenzenesulfonate was employed instead of the polymerizable emulsifying agent.

The results were shown in Table 7.

Table 7 i Monomer composition Emulsifying agent Example Ethyl Acrylo- Divinyl- Fumalic Monobutyl Methucrylic Acrylic Sodium sulfo Sodium dodecyl- No. aerylate nitrile benvene acid itacouate I acid acid prop'yl-2- benzene sulfoethylhcxylate male-ate part part lo 90 ll) 0.5 2 3 l7 90 ll) 0.5 5 3 I8 H) 0.5 2 3 l9 )0 l() 0.5 I 5 3 I 20 )0 l() 0.5 2 3 Z l )l) l() 0.5 2 3 Com. fix

7 )0 I0 045 5 3 8 90 ll) 0.5 5 3 9 90 10 0.5 5 g 7 10 90 10 0.5 5 '7 l l 90 It) 0.5 2 3 l' 90 H) 0.5 5 3 Yield of polymer Amount of polymerizable Amount of emulsifying COD of the mixture Processing emulsifying agent present in the mixture agent present in the mixture of filtrate of filtrate and wash water property of the acrylic rubber by of filtrate and wash and wash water mixing roll \VHICI' a P-P- 286 0.3l 2l A 288 0.32 28 A 285 0.29 A 292 0.28 2s A 290 0.38 26 A 287 0.36 27 A 278 0.8] 92 B 276 0.76 88 B 271 0.89 72 B 273 0.84 I 70 11 290 8.12 113 B 2% s 27 125 C As is clear from Table 7, the amount of polymeriz- A pressure polymerization vessel made by stainless able emulsifying agent in the mixture of filtrate and steal was charged with 1500 ml. of deionized water, 3 wash water in Examples 16 to 21 is a little and the g. of sodium'bicarbonate, g. of potassium persulfate chemical oxygen demand is also low. Therefore, the filand sodium sulfopropyltridecylmaleate of the amount trate and the wash water can be discharged as an indus- 40 shown in Table 8. After removing air in the vessel by trial waste without any treatment. Moreover, the proevacuation, 300 g. of the monomer mixture of vinyl cessing property of the obtained acrylic-rubbers is fatchloride, ethylene and isobutylene of which composivorable. In case of Comparative Examples 7 and 8, tion was shown in Table 8 was added to the vessel and water-soluble polymeric material is by-produced since the polymerization was carried out at a temperature of methacrylic acid or acrylic acid being readily soluble in 47C. for 30 hours. Then the obtained latex was taken water i employ in rg q i As a result, the out and the salting out was done with a 10 percent amount of polymerizable emulsifying agent and the aqueous solution of sodium chloride. After heating at chemical oxygen demand are high, and the filtrate and a temperature of 80C. with agitation, the polymer was the wash water can not be discharged as an industrial filtered and washed with 9.7 liters of hot water and waste without any treatment. In case of Comparative 50 dried. 7 Exa ples 9 I 1 the filtrate and the wash water are The amount of emulsifying agent in the mixture of not clean as a result of employing th polymeriz filtrate and wash water and the chemicl oxygen demand emulsifying agent in large quar't'tit e In Case f of the mixture were determined by the same manner as parati e Examples 11 and a Conventional in Example 10. Further, the heat stability and the heat non-polymerizable emulsifying agent is employed and fl bili of h polymer were d t i d, a large portion of the employed emulsifying agen is The heat stability was measured as follows: To lOO discharged in the filtrate and the wash water. Moreparts f the po|ymer were added 5 part f lead Stean h h m l yg n demand is g Further. the rate and 1.7 parts of dibutyl tin'maleate. The comprocessing property of the acrylic rubber obtained in pound was mixed by a mixing roll at a temperature of Comparative Examples is a little bad, especially that in 0 150C. for 10 minutes and a sheet having a thickness Comparative Example 12 is inferior. of 1 mm. was prepared. The sheet was heated at a temt l80 G (1 th t' t'll EXAMPLES 22 To 25 AND COMPARATIVE pera ure of C 1n eer s oven an e ime 1 the color of the sheet turns to dark brown was measured. EXAMPLES 13 TO 14 The heat stability was represented by thus measured Practical Example (lll) of the polymerization process v for preventing environmental pollutions Sodium sulfopropyl-tridecylmaleate was prepared by the same manner as in Example l0 and was employed as a polymerizable emulsifying agent.

The ',heat flowability was measured as follows: A sheet was prepared-by the same manner as in the above measurement and made to pellet was packed in a Koka flow tester equipped with a nozzle having a diameter of 1 mm. and a length of 10 mm. The temperature of the flow tester was elevated at a rate of 6C./min. under a pressure of 200 kg./cm. and the temperature was measured when the flow rate from the nozzle became 2 mmflmin. The heat flowability was represented by thus measured temperature.

The detailed explanation of Koka flow tester is described in Teikichi Arais A Guide to the Testing of Rheological Properties with Koka Flow Tester published by Maruzen Co., Ltd. 1958).

As Comparative Examples 13 and 14, the same pro cedures as in the above Examples were repeated except that sodium lauryl sulfate was employed instead of the polymerizable emulsifying agent.

The results were shown in Table 8.

further at a temperature of 83 for 12 hours. The yield of polymer was 97 percent.

To thus obtained latex were added 1.6 liters of deionized water, 33 g. of sodium sulfobutyltridecy1maleate and 3 g. of ammonium persulfate, and the mixture was uniformly agitated. A polymerization vessel was continuously charged with the above diluted latex and a menomer mixture consisting of 400 g. of methyl methacrylate, 400 g. of styrene and 3 g. of dodecyl mercaptan by a fixed rating pump in the course of polymerization. The polymerization was carried out at a temperature of 70C. for 6 hours of average residence time and the latex was continuously taken out. To the latex taken Table 8 Monomer composition Emulsi- Yield of Amount of Amount of COD of Property fying polymer polymerizaemulsithe Example Vinyl Ethylsohuty- Sodium agent ble cmulsi lying agent mixture Heat Heat No. chlolene lene sulfofying agent present in of filstahil flowride propyl- Sodium present in the mixture trate ity ability trilauryl the mixture of filtrate and decylsulfate of filtrate and wash wash maleate and wash water water water part part g. g. g. p.p.m. min. C.

22 85 I 2 264 0.3l 13 120 119 23 85 10 5 4 276 0.58 24 130 113 24 80 l0 l0 2 268 0.27 12 120 115 80 l0 l0 4 270 0.59 23 I 108 Com. Ex.

I3 85 10 5 3 263 8.42 [38 90 130 I4 80 l0 l0 3 260 8.34 126 90 125 As is clear from Table 8, the amount of polymerizable emulsifying agent in the mixture of filtrate and wash water in Examples 22 to 25 is low and the chemical oxygen demand of the mixture is also low. Therefore, the filtrate and the wash water can be discharged as an industrial waste without any treatment. A conventional non-polymerizable emulsifying agent is employed in Comparative Examples 13 and 14, and a large portion of the employed emulsifying agent is discharged in the filtrate and the wash water. Moreover, the chemical oxygen demand is high. These may cause an environmental pollution. Further, the polymers obtained in Examples 22 to 25, in which the polymerizable emulsifying agent is chemically bonded within the polymer molecule, can give a sheet improved in heat stability and a pellet improved in heat flowability. On the other hand, the polymers obtained in Comparative Examples 13 and 14 are inferior in heat stability and it is assumed that the inferiority is caused by the emulsifying agent adsorbed into the polymer.

EXAMPLE 26 AND COMPARATIVE EXAMPLES 15 TO 16 Practical Example (IV) of the polymerization process for preventing environmental pollutions A pressure polymerization vessel made by stainless steal was charged with one liter of deionized water, 30 g. of sodium sulfobutyl-tridecylmaleate, 10 g. of ammonium persulfate, 5 g. of sodium sulfate, 2 g. of dodecyl mercaptan, 80 g. of methyl methacrylate, 620 g. of butadiene and 300 g. of styrene. The polymerization was carried out at a temperature of 63C. for .12 hours and out was added a 10 percent aqueous solution of sodium chloride to salt out graft-copolymer, and after heat treatment, the graft-copolymer was filtered and washed with 31 liters of hot water of 50C. and dried.

Further, the obtained graft-copolymers were finely divided and blended with polyvinyl chlorid (straight polymer, P 1000), and from which the test samples for lzot impact test and measurement of percent transmission were prepared as follows: To parts of polyvinyl chloride were added 15 parts of the graftcopolymer, 1.5 parts of dibutyl tin mercaptide, 1.0 part of dibutyl tin maleate and 0.5 part of butyl stearate. The mixture was blended by a ribbon blender for 5 minutes, then extruded from an extruder at a screw speed of 45 r.p.m. and at a temperature of C. to prepare pellets. A test sample was prepared from the pellet by pressing for 10 minutes at a temperature of 190C. under a pressure of 200 kg./cm. and lzot impact strength and percent transmission were measured according to the provision of JIS K 6871 and ASTM- D1003, respectively.

As Comparative Examples 15 and 16, the same procedures as in the above Example were repeated except that sodium lauryl sulfate was employed instead of the polymerizable emulsifying agent.

The results were shown in Table 9.

Table 9 Emulsifving agent Amount of Amount of COD of Property polymeriza emulsithe i Example Amount employed in Amount employed in ble cmulsil'ying agent mixture lzot impact Percent N0. the batchwise poly the continuous polyfyingagent present in of filstrength transmerization in the mcrization in the present in the mixture trate mission first half second half the mixture of filtrate and of filtrate and wash wash Sodium sulfo- Sodium Sodium sulfo- Sodium and wash water water butyl-trilauryl butyl-tri lauryl water decyl'malcate sulfate decylmaleate sulfate g; g g. p.p.m. kgcmJem. "/1

26 30 33 1.9 2x so 93 Corn. Ex.

l5 20 33 49.2 290 50 X8 16 S v i 25 27.8 I56 5 8'.

A particle size of polymer in the latex, which was obtained by the batchwise polymerization in the first half in Example 26 and Comparative Examples and 16, was 0.10 n, 0.1 l p. and 0.15 ;1., respectively. It appears that the improvement in impact strength and transparency of shaped article prepared from the compound of the graft-copolymer and polyvinyl chloride is closely connected with the particle size of polymer of the above-mentioned latex.

The amount of polymerizable emulsifying agent in the mixture of filtrate and wash water in Example 26 is a little and the chemical oxygen demand of the mixture is also low. Moreover, the impact strength and the transparency are excellent. For the purpose of obtaining a polymer having excellent impact strength and transparency nearly equal to that in Example 26, the particle size of polymer in Comparative Example 15 is adjusted from the view pointof connection between a particle size and properties, in which a conventional non-polymerizable emulsifying agent is employed. However, the transparency in Comparative Example 15 is poorer than that in Example 26. It is one of causes by which a small amount of the emulsifying agent is adsorbed by the graft-copolymer. Further, the amount of emulsifying agent in the mixture of filtrate and wash water in Comparative Example 15 is much and the chemical oxygen demand is also high. For the purpose of reducing the amount of emulsifying agent discharged with drainage, Comparative Example 16 is carried out by employing a conventional non-polymerizable emulsifying agent in less amount. However, the particle size of the obtained polymer becomes too large, and as a result, the impact strength extremely lowers. It also makes the transparency worse. in spite of the employment in less amount, the amount of emulsifying agent in the mixture of filtrate and wash water in Comparative Example 16 is much and the chemical oxygen demand of the mixture is also high.

EXAMPLES 27 TO 3l AND COMPARATIVE EXAMPLES 17 TO 2l Improved modacrylic fiber ture, l g. of ammonium persulfate dissolved in a small amount of water was added to initiate the polymeri- 20 zation. At the same time as the initiation of polymerization, an aqueous solution of ammonium persulfate was continuously introduced to the vessel so as to provide ammonium persulfate at the rate of l g./hr. The polymerization was carried out for about 5 hours till the polymer yield reached to about 2000 g. During the polymerization, a composition for continuous charging shown in Table 10 was continuously introduced to the vessel to make the obtained copolymer composition uniform. Salting-out was carried out by adding to the obtained latex a 20 percent aqueous solution of sodium chloride in an amount of one-eighth time to the latex. The mixture was heated to a temperature of 90C. to precipitate the copolymer in slurry. Then filtration, washing and drying were carried out to give a powdery acrylic copolymer.

The copolymer composition shown in Table l0 was determined by elemental analysis to nitrogen, chlorine, and, as occasion demands, sulfer.

In case of Examples 27 and 28 and Comparative Example 17, sodium dodecylbenzenesulfonate of a usual emulsifying agent was employed together with the present polymerizable emulsifying agent in order to increase the stability of latex since sodium sulfopropyllaurylmaleate was employed-.in a comparatively small amount.

phenyl phosphite, and the mixture was dissolved to prepare a spinning solution in concentration of 23 percent.

The viscosity of the spinning solution was in the range of 40 to poises at a temperature of 50C. Then the spinning solution was extruded through the spinneret of nozzle number 300, nozzle diameter 0.1 mm., into the coagulating bath consisting of the same organic solvent as employed in the spinning solution and water, in other words, acetone and water.

The concentration of the coagulating bath was 10 percent, 20 percent, 30 percent or 40 percent, and also the temperature was 10C., 20C. or 30C. The filament formed in the coagulating bath was then introduced into the drawing bath of acetone and water in concentration of 70 percent, and was drawn stepwise to 2 or 3 times the original at a temperature of 30C. Then, the filament was introduced into the washing bath of acetone and water in concentration of 40 percent at 30C. and further introduced into the washing perature of 1 15 to 120C, and thereafter, the filament that the difference .of whiteness of more than about 0.02 can be distinguished by the naked eye. The result of fading was Class 7 in each Example and also the retention ratio to tensile strength was more-than about 80 o was heatdrawn 3 at a temperature of 130 Thus 5 percent and, therefore, the fastness to light was very exobtained drawn fiber of 3 demers was annealed in a hot cellem V o air dryer at a temperature of 145 C. for 3 minutes on the contrary the copolymer obtained in Compar under tension. Thus annealed fiber was employed as a ative Example 17 contained 0.2 percent of sodium sample fiber for the measurement of fastness to light; If I l I aleate and the difference of white Further, the fiber annealed at a temperature of 150C. opropy aury m fb d h d fb for 10 minutes was employed as a sample fiber for the Hess between the annea e 1 er an I measurement of heat Stability were large and, therefore, the modacryhc fiber was in- The result of fastness to light and heat satbility were ferlor in heat Stability Further, the of fading was shown in Table 10, Class 5 and the retention ratio to tensile strength was In table 10 the results in case of the fiber obtained 55.4 percent and,,therefore, the fiber was also inferior under the condition that the concentration of coagulatm fasmess Io hght' The obtained m C Oming bath was percent, the temperature of cogulating P Example ls'contalmed Percent ofsodlum bath was 20C. and the draw ratio in drawing bath was SuIfOP PY y F and the heat stability and 3 were shown since these parameters did not influence the fastness to light of the modacrylic fiber prepared upon the fastness to light'and the heat stability. 20 therefrom were superior, but in case of dyeing the fiber Table 10 Composition for polymerization Q Yield Example Initial charging Continuous charging of No. polymer Acrylo- Vinyl Sodium Sodium Sodium Sodium Sodium Acrylo- Sodium Sodium' Sodium nitrile chloride sulfomcthn onosulfododecylnitrile sulfomono-' sulfopropylallyl lauryl propyl benzene propyl'-' lauryl propyl laurylsulfoitacomethsull't lauryl itacomethmaleate mite noxy acrynate maleate noxy acrypropane late propane late sulfosulfopart part 17.5 82.5 0.5 45.6 2.5 100.2 31 17.5 82.5 0.7 45.6 3.3 99.6 om. Ex

Properties 'of modacryl ic fiber Acrylo- Vinyl Sodium Other poly- Heat stability Fastness to light nitrile chloride sulfomerizable propylmaterial whiteness whiteness Difference Fastness. Tensile Tensile Retention laurylof drawn of of to light strength strength to maleate fiber annealed whiteness before after tensile fiber exposure exposure strength (a) (1)) (11-21) (G'IG (G) (G') X 100) 72 Class g./d. gJd. X

The copolymers obtained in Examples 27 to 31 con- I with cationic dyestuff, uneven dyeing occured due to the strong affinity tody'estuffs of the fiber. Also, the copolymer had the'disadvantage that it was hardly controlled to remove the solvent in the coagulating bath and the transparent drawn fiber was hardly obtained; since the hydrophilic property of the copolymer was too strong. Each copolymer obtained in Comparative Examples 19 to 21 included a conventional polymeriz- 

1. A COMPOUND HAVING THE FOLLOWING GENERAL FORMULA
 2. The compound of claim 1, wherein said R is alkyl group having 12 carbon atoms, said M is Na and said n is
 3. 3. The compound of claim 1, wherein said R is alkyl group having 8 carbon atoms, said M is Na and said n is
 3. 4. The compound of claim 1, wherein said R is alkyl group having carbon atoms substantially distributing in the range of 9 to 15, said M is Na and said n is
 3. 